188 GENERAL SYSTEMATIC BACTERIOLOGY 



1874. Haud scio citrum eandem an aflfinem speciem ill. Billroth in aqua carnis 

 foetida detexerit. 



Cohn believed that the organism which he described was the same 

 as that of BiUroth, hence the choice of name. He also concluded 

 that the Ascococcos parvus of Billroth was not a true Ascoccocus in 

 the sense of Billroth's original description. 



Cienkowski (1878, p. 12) described an organism responsible for a 

 gummy or viscous fermentation of syrups in sugar factories. He re- 

 garded it as confonning to Cohn's conception of Ascococcus and named 

 it A. mesenteroides. A study of the same organism was made by Van 

 Tieghem (1878, p. 198). He concluded that this form was distinct 

 from Ascococcus Cohn and made it the type of the genus Leuconostoc. 

 He called attention to the points of difference between the two genera. 

 In Ascococcus the cells are spherical, very small, and grouped in great 

 numbers to form globular or avoid families which are lobed more or 

 less irregularly. The cells are closely united, separated only by a small 

 amount of gelatinous material ; each family is surrounded by a cartilag- 

 inous envelope. In Leuconostoc the cells are arranged in bent chains 

 separated from each other by a large amount of gelatinous material, 

 the gelatin on the exterior not being thicker than that between the 

 chains. The Ascococcus of Cohn grew in ammonium tartrate solution, 

 the Leuconostoc in sugar and rendered the solution decidedly acid. 

 He places the genus Leuconostoc among the Nematogenae in Cohn's 

 classification, while Ascococcus is with the Glaeogenae. 



Trevisan (1879, p. 137) reworded Cohn's description as follows: 

 "Cellulae globosae, inordinate in colonias conglobotas pluristratas 

 densissime consociatae, tegumentis propriis nullis. Coloniae tegumento 

 communi gelatinoso-cartilagineo crassissimo obvolutae. " He included 

 it in the subtribe Sarcineae. 



Ascococcus Billroth was recognized by Magnin (1880, p. 96) with 

 the species A. billrothii Cohn. Winter (1880, p. 47) hkewise recognized 

 the genus as Ascococcus Cohn. He questions, however, the value of 

 Cohn's genus and also whether the genera of Cohn and Billroth are 

 based upon the same form. He believes it probable that Ascococcus 

 Cohn is only a developmental stage of Micrococcus Cohn. 



Van Tieghem (1880, p. 150) recognized the genus, and added to it 

 the species Ascococcus vibrans from the surface of water in which Beg- 

 giatoa was putrefying. 



Grove (1884, p. 15) used practically the same words as Winter in his 

 discussion of the genus. Van Tieghem regarded Ascococcus as a subdi- 

 vision of Micrococcus including those forms with cells embedded in gelatin. 



